Backups uploader worker for cloudflare r2

cloudflare-worker-r2-backup.js

export default {
  async fetch(request, env, ctx) {
    return await backupHandler(request, env, ctx)
      .catch((error) => new Response(`${error}`, { status: 500 }));
  },
};

const backupHandler = async (request, env, ctx) => {

  if (request.method != 'PUT') {
    return new Response(null, { status: 405 });
  }

  const token = env.TOKEN;
  const bearer = request.headers.get('authorization')?.replace(/^bearer\s+/i, '');

  if (token && token != bearer) {
    await new Promise(resolve => setTimeout(resolve, 1000 + (Math.random() * 500)))
    return new Response(null, { status: 403 });  
  }

  const path = new URL(request.url).pathname.slice(1);

  if (!path.replace(/[\\\/.]+/g, '').length || /[\\\/]$/.test(path)) {
    return new Response(null, { status: 400 });
  }

  const r2 = env.BUCKET;

  if (await r2.get(path)) {
    return new Response(null, { status: 409 });
  }

  const body = await request.blob();
  if (!body.size) {
    return new Response(null, { status: 411 });
  }

  await r2.put(path, body)
  
  return new Response(null, { status: 201 });
};